Numerical Modeling Of Stability Research Articles

Roof Stability of Rectangle Coal Roadway: In Light of Calculation of Compressive Bar Stability

The roadway roof is a key factor to the roadway stability. The analysis of roof stability is mainly based on numerical calculation and on-site observation, while the basic theory of the bearing mechanism is relatively weak. We have founded a critical pressure calculation model, on the theory of compressive bar, for the rectangle coal roadway stability. The model has been tested and verified on accuracy and feasibility while applied on a roadway case. The critical pressure for roof stability and roof bending moment and deflection under combined axial and lateral load was deduced using the theory of compressive bar stability. The numerical calculation verified the feasibility of numerical modeling of stability of compressive bar using FLAC3D, and the influence of the background ambient horizontal stress and the parameters of the contact surface to the roof stability were further studied. The result turns out that some factors lead to a higher instability tendency, including higher horizontal stress, higher cohesion force, and larger internal friction angle on the coal-rock interface and lower cohesion force and smaller friction angle on the rock-rock interface. The results contribute to bearing mechanisms of roadway roof stability, ground pressure and strata control theory and application, and design of bolting support.

Hydraulic Stability Analysis of Armor Units

A numerical stability model is developed to predict the hydraulic stability of armor units on rough slopes under the action of specified normally incident wave trains. The drag, lift, and inertia forces acting on an armor unit are expressed in terms of the fluid velocity and acceleration on a rough slope, which are predicted separately using a numerical flow model. The stability model predicts the variation of the local stability number along the slope whose minimum value corresponds to the critical stability number for initiation of armor movement. The computed critical stability number for riprap is shown to be in good agreement with observed zero‐damage stability number, although some of the input parameters for the model need to be calibrated. Finally, a simplified analysis is performed to predict the sliding morion of armor units on a rough slope. The predicted displacement of armor units may be related to the degree of damage resulting from armor movement.